Pulsator, and more particularly pulsator for milking machines



Oct. 3, 1944. K.'A. BERGSTEDT 2,359,508

PULSATOR, AND MORE PARTICULARLY PULSATORS FOR MILKING' MACHINES F iledMarch 19, 1941 Patented Oct. 3, 1944 PULSATOR, AND MORE PARTICULARLYPULSATOR FOR MILKING MACHINES Karl Abdon Bergstedt, Lindesberg, SwedenApplication March 19, 1941, Serial No. 384,175 In Sweden February 17,1940 8 Claims.

The present invention refers to improvements in pulsators, and moreparticularly pulsators for milking-machines.

The principal object of the invention is to provide a pulsator themovements of which are both distinct and independent of the variablevolume of the conduits connected to the pulsator. Other objects willappear as the description proceeds.

The improved pulsator according to the invention will be described onthe assumption that it is intended for use in connection withmilkingmachines, but this does not mean that the invention isinapplicable to pulsators intended for other purposes, and the inventionis therefore not to be considered limited to milking-machine pulsators.

Generally, in milking-machines the pulsator serves to put a number ofconduits connected with teat cups or the like into communicationalternately with a source of vacuum and with the atmosphere. Theimproved pulsator according to the invention is of the type in which themovable parts are driven by two diaphragms which produce the governingmovements of the pulsator by being subjected alternately to vacuum andpressure. Of the two diaphragms one has a greater active surface thanthe other, and both diaphragms co-operate with a valve slide eitherdirectly or indirectly by the intermediary of a suitablemotion-transmitting member. According to the invention, each of thediaphragms on both sides borders on rooms or chambers which by passagescommunicate in such manner with passages or grooves provided in thevalve slide that said chambers are alternately put into communicationwith the source of vacuum and with the atmosphere, one diaphragm (thelarger one) determining the main movement and the frequency ofalternations of the slide at the reciprocation thereof, while the otherdiaphragm (the smaller one) serves to complete and accelerate themovement of the slide when passing an intermediate cut-ofi positionwhich will be referred to as the central position in the following.

The invention may be embodied substantially in two forms. In one of themboth diaphragrns are rigidly connected with the valve slide, and in theother only the smaller diaphragm is rigidly connected with the slide,while the larger one actuates the slide through an intermediate memberWhich permits a certain free or idle motion or play of the diaphragmrelative to the slide in the direction of movement thereof. In the caseof longitudinally displaceable valve slides this intermediate membermay. preferably consist of a spindle passing through and displaceable inthe slide in the direction of displacement thereof, said spindleactuating the slide by means of suitably provided abutments.

In this connection it should also be noted that the invention is notlimited exclusively to longitudinally displaceable slides, althoughthese are preferred because of the resultant constructional simplicity.

In the following the invention will be described with reference to theaccompanying drawing which diagrammatically shows two forms thereof inlongitudinal section and in which:

Figure 1 shows a form in which both diaphragms are directly connectedwith the valve slide, and

Figure 2 shows a form in which only the smaller diaphragm is directlyconnected with the slide, while the larger diaphragm is arranged toactuate the slide through an intermediary member.

In both figures, the same reference numerals are used to designatesimilar parts.

It should be noted that both figures show the valve slide in the centralposition defined above which is highly unlikely when the pulsator is atrest, but if the slide should stop in this position, the pulsator mayeasily be started again by giving the slide a slight push or by rapidlymoving the pulsator axially, so that the slide will be slightlydisplacedowing to the action of inertia.

The invention may be most simply described by reference to the operationof the pulsator, which is substantially the same for both disclosedforms thereof. It will be assumed that the slide I initially is a littleto the right of the central position shown in the drawing.

The vacuum will then be rapidly transmitted through the conduit 4communicating with the source of vacuum and the passage I l to thechamber I2 on the outside of the smaller diaphragm 8, both diaphragmsbeing moved to the right, taking the slide 1 along the full valveopening. This connection is established through the intermediate Valvegroove in the slide 1, the passage 1 I and the branch passage connectedthereto and leading to the above-mentioned chamber. The passage II isalso connected to the chamber it on the outside of the larger diaphragm9, through the intermediary of a throttle valve I5 (needle valve or thelike) which by suitable adjustment determines the time taken for thetransmission of the vacuum to chamber I l. The position of this valveaccordingly determines the frequency of the pulsations per unit of time.

Gradually, however, the vacuum will be transmitted also to chamber I4,and as it approaches the same value as that in chamber I2, the diaphragm9 will be drawn to the left due to its greater area. Thereby theatmospheric air will be given entrance to the chamber I2 through axialchannel I6 in Fig. 1 (or channel means 6 in Fig. 2), the rightmost valvegroove in the. slide and the channel ll, whereas a vacuum issimultaneously created in the chamber l3 transmitted through themiddlemost valve groove in the slide and the channel I0. As the chamberI4, due to the throttle means I5, is still under vacuum, the slide willbe rapidly thrown over into its leftmost end position. The atmosphericair will gradually enter the chamber I4 through the throttle means I5,however, whereby the diaphragm system will begin to move to the rightunder influence of the vacuum within the chamber l3. Thereafter the samecourse of functioning will be repeated but in the reversed direction.Hence the slide will be moved forwards and backwards with a rapiditydetermined by the adjustment of the throttle means.

It is to be noted that for exact function it is required that the inletopenings to the passages II] and II as seen in the axial directionshould have a greater dimension than the corresponding openings to thepassages 2 and 3 which are assumed to lead to the teat cups of the.milkingmachine, so that the passages I and II are uncovered one momentbefore the passages 2 and 3. Naturally, the same result could also beattained with passage openings having equal axial dimensions, ifthe'valve grooves in the slide are made such as to converge toward thepassages l0 and II.

The form according to Figure 2 difiers from that shown in Figure 1 onlyin the respect that the largeridiaphragm 9 is not directly connectedwith the slide I but with a spindle II axially displaceable through thelatter, screw means for securing the diaphragm to said spindle servingas an abutment to the slide in one direction and a flange l8 provided atthe free end of the spindle serving as an abutment in the otherdirection of movement. The function is the same as described above, butthe diaphragm 9 is given a slightly delayed action on the movement ofthe valve slide, and thereby more distinctly marked slide movements areobtained.

In both forms the slide 1 or I is assumed to be round and displaceablymounted in a boring lined with a sealing bushing in a surroundinghousing I. However, the slide may also be flat or have practically anycross section, the construction or form of the housing being or noimportance to the invention; it can be varied as required Besidesserving as a timing throttle valve the valve I may also be used to bringthe pulsator into andout of operation, and by correct attendance on thisvalve at the stopping of the pulsator, it may also be ensured that theslide will not stop in the central position, so that the pulsator willagainstart without further ado when the valve is opened. 7

In the foregoing it was suggested that the conduits 2 and 3 may beassumed'connected to the teat cups of the milking-machine, and accordingto the number of teat cups connected, the number of such conduits may ofcourse vary, if desired by branches from one conduit. 'During itsrecipro nected to thepassages l0 and II, but such a construction isunsuitable, for in that case both these conduits as a whole and teatcups, etc., connected thereto, which may contain much air and are of anon-predetermined volume, must be filled and emptied before the pressuredifferences in the chambers bounded by the diaphragms can have anyinfluence on the function of the pulsator. It is for this reason thatboth the teat cup conduits and the supply conduits for atmospheric airhave been provided with inlet openings separate from the passages It andII, and in the constructions shown in the drawing it is of importancethat the inlet openings of the passages I0 and l I should have the samedimension in the axial direction as the sealing intermediate portions ofthe slide between the groove-shaped valve channels therein, while theopenings of the passages 2 and 3 have a smaller axial dimension.

Thereby the inlets to the passages I0, II will be'uncovered as the slidepasses the central po-.

sition one moment before the inlets to the passages 2 and 3, so that thepressures or vacua, respectively, have time to betransmitted to thediaphragm chambers before any pressure reduction is produced through theconduits 2 and 3 which causes the slide to be reversed rapidly and withcertainty irrespective of the volume of the conduits 2 and 3 and thecavities connected thereto.

What I claim and desire to secure by Letters Patent is:

l. A pulsator, comprising a housing, valve means movable in saidhousing, two diaphragms having flexible portions of different sizemounted within said housing and dividing it into three chambers, saiddiaphragms being bperatively connected with said valve means, passagesconnecting said valve means with the chambers in said housing, arestriction in the passage leading to one of the chambers bounded by thediaphragm with the larger flexible portion, conduits leading from saidhousing to an outside vacuum source and to outside vacuum consumers,respectively, and a passage connecting said valve 5 means with theatmosphere.

2. A pulsator, comprising a housing, valve means movable in saidhousing, two diaphragms having flexible portions of different sizemounted within said housing and dividing it into three chambers, saiddiaphragms being rigidly con nected with said valve means, passagesconnect-- having flexible portions of different size mounted within saidhousing and dividing it into three chambers, one of said diaphragmsbeing rigidly connected with said valve means and the other beingconnected with said valve means with some play, passages connecting saidvalve means with thechambers in said housing, a restriction in thepassage leading to one of the chambers bounded by the diaphragm with thelarger flexible portion, conduits leading from said housing to anoutside vacuum source and to outside vacuum consumers, respectively, andpassages connecting said valve means with the atmosphere.

4. A pulsator, comprising a housing, valve,

means movable in said housing, two diaphragms having flexible portionsof different size mounted within said housing and dividing it into threechambers, the smaller diaphragm being rigidly connected with said valvemeans and the larger diaphragm being connected with said valve meanswith some play, passages connecting said valve means with the chambersin said housing, a restriction in the passage leading to one of thechambers bounded by the diaphragm with the larger flexible portion,conduits leading from said housing to an outside vacuum source and tooutside vacuum consumers, respectively, and passages connecting saidvalve means with the atmosphere. r

5. A pulsator, comprising a housing, valve means movable in saidhousing, two diaphragms having flexible portions of different sizemounted adjacent each other within said housing and dividing it into twochambers bounded each by one of the diaphragm portions and oneintermediate chamber bounded by both diaphragm portions, said diaphragmsbeing operatively connected with said valve means, passages connectingsaid valve means with the chambers in said housing, a restriction in thepassage leading to the chamber bounded by the larger diaphragm portiononly, conduits leading from said housing to an outside vacuum source andto outside vacuum consumers, respectively, and a passage connecting saidvalve means with the atmosphere.

6. A pulsator, comprising a housing, valve means movable in saidhousing, two diaphragms having flexible portions of difierent sizemounted within said housing and dividing it into three chambers, saiddiaphragms being operatively connected with said valve means, passagesconnecting said valve means with the chambers in said housing, throttlemeans inserted in the passage leading to one of the chambers bounded bythe diaphragm with the larger flexible portion, conduits leading fromsaid housing to an outside vacuum source and to outside vacuumconsumers, respectively, and a passage connecting said valve means withthe atmosphere.

7. A pulsator, comprising a housing, valve means movable in saidhousing,'two diaphragms having flexible portions of different sizemounted within said housing and dividing it into three chambers, saiddiaphragms being operatively connected with said valve means, passagesconnecting said valve means with the chambers in said housing, anadjustable throttle valve needle inserted in the passage leading to oneof the chambers bounded by the diaphragm with the larger flexibleportion, conduits leading from said housing to an outside vacuum sourceand to outside vacuum consumers, respectively, and a passage connectingsaid valve means with the atmosphere 8. A pulsator, comprising ahousing, valve means movable in said housing, two diaphragms havingflexible portions of different size mounted within said housing anddividing it into three chambers, said diaphragms being operativelyconnected with said valve means, passages ending in the chambers in saidhousing, valve openings in said housing co-operating with said valvemeans and forming terminals of said passages, a restrictionin thepassage leading to one of the chambers bounded by the diaphragm with thelarger flexible portion, conduits leading from said housing to anoutside vacuum source and to outside vacuum consumers, respectively,valve openings in said housing co-operating with said valve means andforming the inner terminals of the conduits leading to the vacuumconsumers, the lastmentioned valve openings having a width relative tothe width of the firstmentioned valve openings such as to be lateruncovered and earlier covered by said valve means at the movementthereof than the latter openings, and a passage connecting said valvemeans with the atmosphere.

KARL ABDON BERGS'I'EDT.

